Field of the Invention
A candle is simply a combustible, porous core or wick surrounded by a fusible, flammable solid, such as a wax or waxlike material. When the candle is lit, the heat from the flame melts the solid and the resulting liquid then flows up the wick by capillarity. This liquid is subsequently vaporized and becomes part of the innermost of three layers in the flame. The middle zone of the flame is where the vapor is partially decomposed, and the outer layer is marked by combustion of the vapor and the emission of carbon dioxide, water and other vapors into the atmosphere.
Candles, particularly those enclosed in plastic or glass containers, such as votive candles, generally require a stiffened wick. A limp wick may extinguish itself in the pool of liquid wax lying just below the flame of the burning wick. Another disadvantage of a limp wick in these types of candles is the possibility that while burning, the wick and flame could bend enough to make contact with the side of the container and cause breakage or other damage.
It is customary to stiffen the wicks of these kinds of candles by forming the wicks around a fine lead wire. When the wick is burned, the lead strand conveniently melts or vaporizes and leaves no undesirable residue to plug the porous wick and disrupt its capillary action. However, the lead vapors emitted into the atmosphere are toxic and may create a health hazard under certain conditions. As a result, an alternative, non-toxic stiffening agent for the wicks is desirable.